1. Field of the Invention
The invention relates to a method for manufacturing a piezoelectric film wafer, a piezoelectric film element and a piezoelectric thin film device.
2. Related Art
A piezoelectric material is processed into various piezoelectric elements in accordance with different purposes, particularly, it has been widely used for functional electronic components such as an actuator for generating deformation by applying voltage or sensor for generating voltage from the deformation of elements in a reverse way, etc.
As the piezoelectric material used for an actuator or a sensor, a lead (Pb)-based dielectric material having large piezoelectric characteristics, especially, Pb(Zr1-xTix)O3-based perovskite-type ferroelectric called as “PZT”, has been widely used, and the piezoelectric material is formed by sintering oxide which is generally formed of individual elements.
In recent years, it is desired to develop a lead-free (Pb-free) piezoelectric material from environmental consideration, and thus, potassium sodium niobate (general formula: (K1-xNax)NbO3 (0<x<1)), hereinafter referred to as “KNN”, etc., has been developed. Since the KNN has piezoelectric characteristics comparable to PZT, it is expected as a potential candidate for a Pb-free piezoelectric material. Examples of a Pb-free piezoelectric film with this kind of piezoelectric material are proposed in the JP-A 2007-19302 and JP-A 2007-184513 for example.